AwkwardPotato

Just noticed something -- in the pictures you posted, it looks like many of the 10uF capacitors (C7, C6, C111, C5, C1, C3, C105, C108) have been replaced with 100uF parts. This may be at least part of the problem.

Here's a chart with all the size codes: http://www.resistorguide.com/resistor-sizes-and-packages/. The three numbers on the top of the resistors tell what the resistance is: https://www.hobby-hour.com/electronics/smdcalc.php.

Opened up my MP-F75W-11G to check and there are two different sizes of resistors on the PCB. Smaller ones are 0805 case code (imperial), and larger ones are 1206 case code (also imperial).

If you really want to repair the pads for C13 or any of the other capacitors, I suppose you could find a sheet of copper foil (without adhesive, can be found on Amazon), cut new pads from it, and attach them to the board with a high-temperature-resistant epoxy (I know such a thing exists but I can't seem to find it atm). The way I've dealt with this in the past, albeit far less professional, was to cut off the barely remaining pads, solder a jumper wire to each of the pads on the bottom of the capacitor, hot-glue it in place, and then solder the jumper wires where necessary. If it were me, I would stop rocking the caps and heating each side with the soldering iron. This board appears to be in very rough shape, so I'd recommend that you use as little heat as possible to remove the caps. It would be a better idea to wiggle each one off with a pair of pliers veeery slowly. Start rocking it only slightly, perpendicular to the leads. After a while you'll feel it loosen up and eventually the leads will break off above the plastic base. The remaining leads can then be desoldered and the pads can be wicked clean. Kynar wire-wrap wire (28-30AWG, can also be found on Amazon) works very well for jumper wire.

Although I had a few issues with the video as well, I'm hoping it'll spread the word about recapping some, especially seeing how big his audience is on YouTube. It seems that a lot of people into classic Macs still don't realize just how damaging caps can be. Re: the twisting caps method, respectfully, I don't think it's as dangerous as people make it out to be. Although a newcomer to the hobby might not know the difference, if your board is still in "okay" shape, it works fine, provided that you're gentle (based off purely empirical evidence, 5x 68k's of mine). Also bear in mind that the heat from desoldering can damage pads too. I totally agree with your points on lack of ESD safety & the dishwasher though, it was frustrating to see that in the video.

It appears you can get both the SCC and SCSI controller off eBay for roughly $10 each (not my listings). BTW, when buying obsolete parts like these, it's wise not to buy from sellers in China as they have a reputation for relabelling parts as others.

I don't mean to be rude, but you haven't created some "System 6 for Windows" thing; you've bundled Mini vMac, an open source emulator that most, if not all of the members here are well aware of, with a copyrighted ROM/OS, property of Apple. It's hardly anything new.

I'm pretty sure that you would at least get a raster on the display if the SCSI and/or SCC chips were bad. After seeing all the crud that was under the Bourns filters, though, I'm wondering if there's more under one of those chips and it's shorting some signals together.

Almost certainly a power supply issue, then, given that the hard drive starts spinning down.

I've never heard of it failing, but maybe try swapping that big socketed VLSI chip next to the CPU, just to rule it out (just be very gentle to prevent cracking the socket). Also, maybe there's a rotted trace under the SCC or SCSI chip?

What exactly happened when the computer "shorted out"? This sort of sounds like a PSU problem. Was every cap in the PSU replaced? Some guides say to only replace a few, which is false.

Thank you, my mistake.

The power switch, at least on my PSU, has a few wires soldered to it and is clipped into the back of the metal case.

Sounds like a really nice machine, but given that it isn't recapped I'd probably say closer to $150-$200. The SE/30 is almost infamous for cap issues.

10uF is way too high for an oscillator circuit like this, try a 33pF cap.